MB - Fatty Acid Metabolism I

Question 1

Why should fatty acids be metabolised?

Answer 1

• They contain a lot of energy
• They form a dense energy store

Question 2

What 3 enzymes are involved in lipolysis?

Answer 2

1. Adipose TG Lipase (ATGL)- TAG –> DAG + FFA
2. Hormone-sensitive Lipase (HSL)- DAG –> MAG + FFA
3. Monoglyceride Lipase (MGL)- MAG –> FFA + Glycerol

Question 3

Where do FFA’s bind to?

Answer 3

Bind to Human Serum Albumin (HSA)

Question 4

What steps are involved in the entry of FFA’s into cells? (5)

Answer 4

1. FA are released from HSA and travel to the outer membrane of a mitochondrian
2. Activated by coenzyme A and ATP
3. The acyl-CoA can now cross the outer mitochondrial membrane
4. CoA swapped for carnitine to cross the inner membrane
5. Acyl-carnitine is transported across the bilayer

Question 5

What is β Oxidation?

Answer 5

The removal of 2 carbon atoms in FAs producing acetly CoA and a shortened acyl CoA

Question 6

What are the 4 main steps involved in β oxidation of FA’s?

Answer 6

1. Oxidation of alpha and beta carbons
2. Addition of a hydroxyl group on beta via hydration
3. Oxidation of beta to form a carbonyl
4. Thiolysis and addition of CoA occur

Question 7

How do you calculate the number of cycles that have occurred?

Answer 7

(#carbons/2) - 1

Question 8

What are ketone bodies and when are they produced?

Answer 8

During periods of starvation FFAs levels rise and so does the build up of Acetyl CoA
- Hence Ketone bodies are made

Question 9

What is Ketogenesis?

Answer 9

Production of ketone bodies when carbohydrate stores are insufficient